Currently, there are heart rate monitor belts which people can wear underneath their clothing in order to monitor their heart rate. Such belts are typically designed such that a telemetric transmitter is detachably connected to a belt having two electrodes which are in contact with the user's skin in the chest region of the user's torso. The electrodes identify an electric ECG pulse caused by the heart and then the detachable telemetric transmitter transmits data indicative of the user's heart beat with the use of wireless magnetic near field communication or a radio signal to a remote receiver provided with a display. In many instances the remote receiver is provided in the form of a wrist watch, wrist top computer or other similar display carried by a user, typically on the user's wrist.
Similarly, the fusion between wearable and ubiquitous computing and outdoor activities like sports, produce equipment with various sensors and electrodes attached to or placed on different parts of the body. The usually passive electrodes and the sensor unit they feed with signals need to be interconnected, and both components need to be detachable for replacement or service.
Since various acceleration and magnetic sensors can be integrated in small and lightweight devices, the telemetric data to be transferred may, instead of or in addition to the heart rate, comprise a plurality of measured variable data, such as working frequency, pedaling rate and pedaling frequency, travel speed, etc. The data to be transferred may additionally comprise data required for the identification of the user and/or the transmitter device.
U.S. application Ser. No. 11/808,391 filed Jun. 8, 2007 and published as US 2007/0285868 which is herein incorporated by reference in its entirety, for instance, discloses a heart rate monitor belt which comprises a plurality of electrodes and a detachable telemetric transmitter.
It is preferably to have a telemetric transmitter or sensor unit which is detachable. From a consumer point of view, a user is typically sweating while using a sports device like a heart rate monitor belt and it is therefore advantageous to be able to separate the electronic device from the belt, shoe or garment that is carrying it, so that the carrier can be washed. From a manufacturing point of view, the process for manufacturing the carrier is substantially different from that of manufacturing a transceiver or sensor unit, and therefore it is beneficial to be able to manufacture the components separately. Additionally, it is usually beneficial if the electronic devices are interchangeable between a plurality of carriers.
Though there are several alternative methods for connecting especially a telemetric transmitter to a heart rate monitor belt containing the necessary electrodes, the industry has almost entirely adopted the use of a pair of standard garment snaps. These standard garment snaps typically are mounted on the material of a heart rate monitor belt and virtually their entire thickness of around 4 mm protrudes from the outer surface of the belt. In principle, snaps provide a convenient way with almost guaranteed user acceptance to both mechanically fix devices in place, and to provide an electrical connection between them.
Due to shortcomings in size and reliability of existing “snap” technology and other methods for detachably connecting health monitoring and sports devices to electrodes, it has not been realistic to incorporate electrodes directly in garments. The primary road block to such incorporation has been the size and bulkiness of the standard garment snaps. No clothing manufacture, nor consumer, has wanted 4 mm protrusions from their garments such as tops, shirts and sports bras.
Therefore, the garment industry has incurred a long felt need for an improved method of detachably connecting a health monitoring or sports device to an article of clothing which does not compromise the integrity and utility of the underlying garment. However, especially the telemetric devices manufacturing industry has adopted certain standards which relate to the use of a pair of male studs on a telemetric transmitter to be detachably snapped in to a pair of snaps on a heart rate monitor belt. As such, it would not be economical to wholly redesign the male portions of telemetric transmitters and the method in which they connect to an object having the necessary electrodes for measuring a user's heart rate.
Thus, there exists a need for a snap which fulfils the requirements of the garment industry but which fits in with the design and production methods of the manufacturing industry. Several critical issues arise when attempting to merely minimize the existing standardized snap. The main issue is the integrity of the connection between the male stud and the snap. Any movement of the male stud within the snap will create electrical noise which makes it difficult if not impossible to accurately measure parameters such as a user's heart beat. Additionally, as a user is typically involved in strenuous activity while utilizing the product, the connection needs to withstand and support the attached device during such activity. As the size and depth of a snap decreases, the more critical becomes the mechanical design of it to withstand the forces, and to ensure a reliably and stable electrical connection under all circumstances becomes a very delicate design problem indeed.
Further yet, users typically sweat while undergoing strenuous activity wearing the product. As a reliable electrical connection is necessary between the sensor device and the connected electrodes on the user's skin, it is important to keep the connection moisture free to reduce the likelihood of any shorts. Similarly, the problem is compounded for users who wish to utilize a heart rate monitor under water, for example while swimming or diving.
Therefore, there exist numerous challenges in the art to the development of a means of detachably connecting e.g. a telemetric transmitter to a garment having electrodes for monitoring a user's heart beat which aims to satisfy user's need, the garment manufacturer's needs and the needs of health and sport goods manufacturers.
Partially the problem has been solved in the co-pending U.S. patent application Ser. No. 13/832,736 by the same applicant, the entire content of which is included herein by reference. In the solution presented, the snap size and thickness has been significantly reduced, and the electrical connection between a male connection portion and a socket region of a snap has been improved. Currently, the standard snap thickness in the industry is around or above 4 mm. With the design of the snap presented in U.S. patent application Ser. No. 13/832,736, the maximum thickness of the snap can be between 1 to 3 mm. Thus, utilizing such a design the overall size of the snap can be reduced by 50-70% or more. This reduction in size enables one to integrate health and sport device electrodes into garments in an acceptable manner.
However, the male portion of a snap has two ends, one being connected to the PCB of the health or sports device, like a telemetric heart rate monitor transmitter, the other end protruding from the device as a stud to be snapped into a socket connected to an electrode. The above mentioned solution addresses the design of the stud end and how it interconnects with the socket. However, also the end of the male portion connected to the PCB (Printed Circuit Board) of the device is subject to the same forces and circumstances as the other end. The problem of securing the fastening and electrical connection between the male portion of the snap and the PCB has previously been solved by providing threads to screw the male portion of the snap into place, by welding it to the plastic case of the device with ultrasound, etc. However, these measures are a solution for the mechanical fastening of the male part, and are directed to the mid-portion of it. The end to be fitted to the PCB has so far been conventionally designed, providing gold plating and a friction-based electrical connection. Also, in order to account for variations in the manufacturing process, an electrical wire may be soldered between the male portion of the snap and the PCB, or spring contacts may be used to improve the connection between the male portion and the PCB. Standard PCB spring contacts are however complicated in construction and require separate assembly, like any other components on the PCB.
During the circumstances and for reasons that have been explained above, there is a need for an improved and simplified connection device. The quality of the electrical connection to the PCB is of course as important as in the other end and is, despite a fairly reliable mechanical fastening, subject to small movements and manufacturing tolerances causing noise. Also, only a minimum amount of wear at the contact surface caused by such movement drastically reduces the signal quality.